 BackResearch Article ScienceAsia 13 (1987): 071-083 |doi: 10.2306/scienceasia1513-1874.1987.13.071
PHYTOCHEMICAL AND PHARMACOLOGICAL STUDIES OF THE FLOWERS OF MILLINGTONIA HORTENSIS LINN. F.*
KALAYA ANULAKANAPAKORN,a NUNTAVAN BUNYAPRAPHATSARAb and JUTAMAAD SATAYAVIVADaABSTRACT: Millingtonia hortensis Linn. f. is an ornamental plant cultivated throughout the country. The dried flowers are not only used for cigarette flavor, but they can also be used as a remedy for asthma. Our attempt to isolate the active constituents was carried out by using pharmacological testing as a tracing tool. Since the methanol extract exhibited bronchodilating effect on isolated rat trachea, this extract was further fractionated into petroleum ether, chloroform, n-butanol and aqueous fractions. Pharmacological studies indicated that the chloroform fraction elicited the most prominent effect. Further separation of the chloroform fraction by short column chromatography enabled hispidulin, the bronchodilating agent, to be isolated. Detection by TLC indicated that hispidulin is one of the compounds present in the smoke of the dried flowers. It is therefore likely that the antiasthmatic. activity of the dried flowers of M. hortensis Linn. f. is due to hispidulin. Hispidulin is more potent than aminophylline on a molar basis. It was interesting to observe that the aqueous extract of these flowers exhibits a bronchoconstricting action which gradually diminishes upon storage. To assure the safety of patients, attempts to study the toxic effects of the crude extracts and hispidulin have been performed. These studies indicated that hispidulin was less toxic than the crude extract. a Department of Pharmacology, Faculty of Science, Mahidol University
Received 21 November 1986
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